Count Rumford[249] stated that threads of silk and wool had the power of decomposing carbonic acid in water in the sunshine; and hence some have referred organization to a mere chemical change produced by luminous excitation; and we have heard of animal life resulting from pounded siliceous matter. All such statements must be regarded as evidences of imperfect investigation. Dr. Carus, alluding to the experiments of Gruithuisen, Priestley, and Ingenhousz,[250] says:--“These show, more than any other experiments, that, in the purest water, under the influence of air, light, and heat, beings are formed, which, oscillating as it were between the animal and the plant, exhibit the primitive germs of both kingdoms.”[251] Treviranus[252] repeated, and appeared to confirm these results; but in these experiments we have no evidence that the germ did not previously exist in the spring-water which was employed. Some have regarded the cell as a crystal; they see the crystal forming, by the accumulation of atoms, into a fixed form, under the influence of an “inner life;” and, advancing but a step, they regard the cell as the result of an increased exercise of the physical influences.[253] We have referred crystalline form to certain magnetic conditions; and it is evident that the atomic cell is influenced by similar forces; but if we place a crystal in its natural fluid, though it increases in size, it never alters in form: whereas, if we examine a cell in its natural position, it gives indications of motion, it produces other cells, and we have a development of organs which are in no respect the same in form as the original. From a vesicle floating invisible to the unaided human sense in its womb of fluid, is produced a plant possessing strange powers, or an animal gifted with volition. The idea, that two kinds of polarity--light on one side, and gravitation on the other--produce the two peculiar developments of roots and branches, can only be regarded as one of those fanciful analogies which prove more imagination than philosophy.[254] The conditions are, however, most curious; they deserve very attentive study; but in examining the phenomena, the safest course is to allow the effects as they arise to interpret to us, and not admit the love of hypothesis to lead us into bewildering analogies; or uncertain phenomena to betray us to hasty inferences. It is of this evil that Bacon speaks, in his “Advancement of Learning.” He says:-- “The root of this error, as of all others, is this, that men, in their contemplations of nature, are accustomed to make too timely a departure, and too remote a recess from experience and particulars, and have yielded and resigned themselves over to the fumes of their own fancies and popular argumentations.”